In recent years, resistance varying memory has been receiving attention as a successor candidate of flash memory. Resistance varying memory normally has a cross-point type structure configured having memory cells arranged in a matrix at intersections of a plurality of bit lines and a plurality of word lines intersecting the plurality of bit lines, each of the memory cells comprising a variable resistance element.
In this kind of cross-point type resistance varying memory, in order to perform a certain operation in a selected memory cell, a certain voltage is applied to a selected bit line and a selected word line. On the other hand, in an unselected memory cell, a voltage of an unselected bit line and an unselected word line is selected to avoid a change in held data. However, a certain amount of stress is inevitably applied to the unselected memory cell, and there is a risk that this stress causes data holding characteristics of the unselected memory cell to deteriorate.